Inbox `show` Test Plan Index

Case Files

Case Slug	File	Coverage Note
`show-returns-thread-and-message-history`	show-returns-thread-and-message-history.md	returns thread details and full time-ordered message history
`show-includes-artifacts-per-message`	show-includes-artifacts-per-message.md	expands per-message artifacts in the show payload
`show-mark-read-advances-read-cursor`	show-mark-read-advances-read-cursor.md	advances caller read cursor when `--mark-read` is used
`show-rejects-when-thread-missing`	show-rejects-when-thread-missing.md	returns stable not-found contract for missing thread